Search results for "lithostratigraphy"
showing 10 items of 12 documents
Palynology and lithostratigraphy of Late Elsterian to Early Saalian aquatic sediments in the Ziemupe–Jūrkalne area, western Latvia
2000
Abstract This study is based upon lithological and palynological investigation of test-drilling cores along the Baltic Sea coast. Three intertill units of basin sediments are underlain by a thin layer of Lētiža (Elsterian) till and overlain by glaciotectonically deformed Kurzeme (Saalian Complex) till. The Kurzeme till differs from the Lētiža till by higher contents of limestone clasts and rounded hornblende grains. The lowermost intertill unit consists of glaciolacustrine to glaciomarine laminated clay of the Sudrabi member, a late glacial deposit of the Lētiža glaciation. Treeless vegetation covered the adjoining land. Next is the marine to brackish Akme n rags formation, deposited during…
Lower Cretaceous formations (Berriasian/Valanginian to Albian) from the East of the Paris Basin: lithostratigraphy and depositional environments.
2023
The Paris Basin is a Meso-Cenozoic intracontinental basin characterised during the Early Cretaceous by a continental evolution. However, in its southeastern part, due to transgressions originating from the Tethys, the Lower Cretaceous continental deposits were occasionally interrupted by the deposition of marine sediments. In this area, the sedimentary succession includes above the Lower Tithonian “Calcaires du Barrois”, the transgressive “Sables de Soulaines” Formation on the Late Jurassic emersion surface. This formation showing facies characteristic of a tidal flat is reputed to be Valanginian in age, but there is no dating element and could as well begin in the Late Berriasian. Above,…
Sinemurian to lowermost Toarcian ammonites of the Brescian Prealps (Southern Alps, Italy): preliminary biostratigraphical framework and correlations.
2009
10 pages; International audience; A set of 28 ammonite biohorizons or faunal assemblages is proposed for the Sinemurian, the Pliensbachian and the lowermost Toarcian of the Brescian Prealps, in part based on the published data of the authors of this contribution and partly on new results, derived both from recent field investigations and from the study of the historical collection of Lower Jurassic ammonites preserved in the Museum of Natural Sciences of Brescia (Northern Italy). The biohorizons are present in the Liassic carbonate succession of the Brescian Prealps, cropping out between the eastern surroundings of Brescia (Botticino), to the east, and Lake Iseo, to the west. Since the Hett…
Coupures morphologiques et biochronologie chez les Kosmoceratinae de l'Est de la France (Callovien inférieur pp. à Callovien supérieur pp.)
1998
Abstract For the first time in eastern France, a detailed succession of the uppermost Lower Callovian to Lower Upper Callovian Kosmoceratinae is presented, according to the fossils collected in situ at Blye (Jura, France). It is compared with the abundant data from Champagne and Bourgogne. These ammonites may allow more accurate correlations between the subboreal and subtethysian biostratigraphical frameworks. They record numerous morphological changes, sometimes different from those generally accepted. They allow the precise recognition of the limits of the biostratigraphical units, and the definition of successive faunal units available in the lowermost Upper Callovian.
The Devonian Stratigraphic Succession and Evolution of the Baltic Sedimentary Basin
2014
Facies analysis, biostratigraphic and taphonomic studies, a re-evaluation of signatures of worldwide events, and a new mathematical model of the Baltic sedimentary basin (BSB) have together enabled a better understanding to be gained of the development of the Devonian basins in the Baltic area. We have established four stages of basin evolution: (a) remnant basin stage (Lochkovian); (b) shallow epeiric basin stage, with mainly siliciclastic sedimentation (Pragian–early Frasnian); (c) shallow epeiric basin stage, with mainly carbonate sedimentation (Frasnian); and (d) infilling stage of the progressively narrowing shallow epeiric basin, with mixed sedimentation (Famennian).
Age and metasomatic alteration of the Mt Neill Granite at Nooldoonooldoona Waterhole, Mt Painter Inlier, South Australia
2001
Quartz feldspar augen gneisses, quartz augen schists and trondhjemites outcrop at Nooldoonooldoona Waterhole in the southwestern corner of the Proterozoic Mt Painter Inlier, northern Flinders Ranges, South Australia. These rocks were previously interpreted as having different origins and ages. However, we argue that all rock types were the result of deformation and strong metasomatic alteration of one common precursor: the Mt Neill Granite. Our conclusion is based on field observations that show that the different lithologies grade into each other and that intrusive contacts are lacking. Whole rock major and trace element analyses also point to a common protolith. Finally, Pb/Pb dating of m…
New lithostratigraphy for the Cantabrian Mountains: A common tectono-stratigraphic evolution for the onset of the Alpine cycle in the W Pyrenean real…
2019
The Pyrenean-Cantabrian Orogen arose through the collision of the Iberian and Eurasian plates, mostly in Cenozoic times. This orogen comprises two main mountain ranges, the Pyrenees to the east, and the Cantabrian Mountains to the west. To date, the early Alpine tectono-sedimentary phases preserved in the Cantabrian Mountains, of Permian and Triassic age, have been considered independently from the same phases in neighbouring basins of SW Europe, and even from the eastern part of the same orogeny (the Pyrenean orogeny). In consequence, the beginning of the Alpine cycle in the Cantabrian Mountains has been interpreted within a specific geodynamic context, far from the general evolutionary ph…
Sedimentary environment, lithostratigraphy and dating of sediment sequences from Arctic lakes Revvatnet and Svartvatnet in Hornsund, Svalbard
2016
Abstract The sedimentary environment, sediment characteristics and age-depth models of sediment sequences from Arctic lakes Revvatnet and Svartvatnet, located near the Polish Polar Station in Hornsund, southern Svalbard (77°N), were studied with a view to establishing a basis for paleolimnological climate and environmental reconstructions. The results indicate that catchment-to-lake hydroclimatic processes probably affect the transportation, distribution and accumulation of sediments in different parts of lakes Revvatnet and Svartvatnet. Locations with continuous and essentially stable sedimentary environments were found in both lakes between water depths of 9 and 26 m. We used several diff…
Miocene lithological, foraminiferal and palynological data from the Belverde borehole (Portugal)
2021
XVIII Jornadas de Paleontología, 2002 Preliminary data on litho stratigraphy and biostratigraphy of the Belverde borehole (http://www. dct.Jct.unl.pt/ SondagemISondagem/colunalindex_col.html) is presented. The borehole attained 619,77 m of depth, crossing 130 m of Plio-Pleistocene and 460 m of Miocene dep osits. Main lithologies are fine sands , marl s and biocalcarenites. A coral reef was recognized in the lower part of the borehole (530-585 m). Gamma ray, neutrons and sonic diagraphies were obtained. Eight 87Sr/86Sr isotopic ages (H. Elderfield, Cambridge University)and the presence of some of the main planktonic foraminifera markers were used to establish the chronostratigraphic framewor…
Resumen cronoestratigráfico de las rocas ígneas de Costa Rica basado en dataciones radiométricas
1992
Resume El presente trabajo recopila los resultados de aproximadamente 160 dataciones radiometricas K-Ar y U-Th que se han realizado en Costa Rica en los ultimos 20 anos. Con base en estas dataciones y en relaciones estratigraficas se establecio un cuadro cronoestratigrafico sobre la evolucion del magmatismo desde el Mesozoico hasta el presente. Las rocas igneas del Jurasico hasta el Oligoceno se caracterizan por su tendencia toleitica. A partir del Mioceno tardio predominan rocas de la serie calcoalcalina y la actividad volcanica culmina en el Pleistoceno con la erupcion de grandes volumenes de ignimbritas en la parte norte y central de Costa Rica y la edificacion de los estratovolcanes de …